The role of space, dispersal and active movement in fungal community assembly

Most of the theory of community ecology has been developed studying the unitary organisms. Therefore, the applicability of established theory to modular organisms remains unclear. Here we present theoretical developments that allow the community ecology of modular organisms to be firmly embedded within the established community ecology frameworks of modern coexistence theory and movement ecology. Within modular organisms, our primary focus is on filamentous fungi. The interplay of space and movement of organisms is critical for community assembly and species coexistence. Several research areas such as metacommunity theory, modern coexistence theory, and movement ecology aim to describe this interplay for animals and plants. These disciplines have assembled theoretical knowledge about the persistence and dynamics of biological diversity that is intended to be universally applicable to living systems. Applying theoretical concepts largely developed for unitary macro-organisms to filamentous fungi is challenging given their modular, network-like body structure. Here, we reviewed relevant knowledge from modern coexistence theory, movement ecology, and fungal ecology and developed two concepts that enable the application of established community ecology to filamentous fungi. We named these concepts unit of community interactions (UCI) and active movement of fungi. The first concept provides an operational definition of individual and population that is central to modern coexistence theory, but is problematic for clonal/modular life forms. This concept is introduced in the first chapter of this thesis along with modern coexistence theory applied to fungal systems. In the second chapter, we introduce the concept of active movement in fungi, demonstrating how the framework of movement ecology can be applied to filamentous fungi at all relevant spatial scales. We show that in modular organisms, physiological and morphological movements have a coupled ecological function and can thus influence community assembly via processes predicted by movement ecology. We further demonstrate this in the third chapter, where we describe the development of an agent-based model of hyphal dispersal in micro-structured environments and provide an initial evaluation of the model

The role of active movement in fungal ecology and community assembly

Movement ecology aims to provide common terminology and an integrative framework of movement research across all groups of organisms. Yet such work has focused on unitary organisms so far, and thus the important group of filamentous fungi has not been considered in this context. With the exception of spore dispersal, movement in filamentous fungi has not been integrated into the movement ecology field. At the same time, the field of fungal ecology has been advancing research on topics like informed growth, mycelial translocations, or fungal highways using its own terminology and frameworks, overlooking the theoretical developments within movement ecology. We provide a conceptual and terminological framework for interdisciplinary collaboration between these two disciplines, and show how both can benefit from closer links: We show how placing the knowledge from fungal biology and ecology into the framework of movement ecology can inspire both theoretical and empirical developments, eventually leading towards a better understanding of fungal ecology and community assembly. Conversely, by a greater focus on movement specificities of filamentous fungi, movement ecology stands to benefit from the challenge to evolve its concepts and terminology towards even greater universality. We show how our concept can be applied for other modular organisms (such as clonal plants and slime molds), and how this can lead towards comparative studies with the relationship between organismal movement and ecosystems in the focus